二次元 液體 He의 Third-sound Velocity에 의한 Elementary Excitation Spectrum 및 Thermodynamic Functions

趙東山,吳喜均 全南大學校 師範大學 科學敎育硏究所 1982 科學敎育硏究誌 Vol.7 No.1

Regarding liquid 4He as a real boson system interacting with a soft potentiaL plus a Lennard-Jones type tail, elementary excitation spectrum and several thermodynamic functions are explicitly evaluated with the parameters determined by the third-sound velocity in two-dimensional liquid 4He at density of 1.77 atomic layer. The excitation spectrum and thermodynamic functions are characterized by the Landau-type quasiparticles and the phonon dispersion relation is anormalous. The third-sound velocity evaluated on the basis of the microscopic theory of two-dimensional hard sphere bose gas is in good agreement with the data measured at coverage of 1.77 atomic layer by Rutledge- McMillan -Mochel and Washburn (RMMW)

遷移金屬 酸化物系 유리半導?의 電氣的 特性에 關한 硏究

趙東山,吳喜均 全南大學校 師範大學 科學敎育硏究所 1980 科學敎育硏究誌 Vol.5 No.1

Vanadium phosphate glasses containing several transition metal oxides such as Fe2O3, MoO3, Cr2O3, CuO, have been prepared and then their electrical characteristics have been investigated. Electric conductivities increase with increasing the content of the transition metal oxides and the ambient temperature. Activation energies for the electric conduction are constant in the temperature above 330°~340° K and they decrease gradually below that temperature region. It is believed that the electric conduction mechanism in these transition metal oxide glasses is the electron hopping process between transition metal ions. Electrical switching phenomena have been observed in the glasses containing more than 60 molar percent of V2O5. Threshold voltages decrease with increasing content of V2O5 and ambient temperature. The thicker the glass sample, the lower the breakdown field. And threshold voltages are inversely proportional to the root of electric conductivities. These results have been discussed by the electronic theories and thermal theory for the electrical switching phenomena, and can be explained by the thermal model based on the Joule heating of the sample.

V2O5 : Fe2O3 Glass의 電氣的 Switching 特性

趙東山 全南大學校 師範大學 科學敎育硏究所 1979 科學敎育硏究誌 Vol.4 No.1

V2O5: Fe2O3: P2O5 glasses have been prepared. It has been found by the investigation on the area of glass formation that the compositions with more than 30 molar percent of Fe2O3 do not form glass. Glasses containing more than 70 molar percent of V2O5 show the electrical threshold switching phenomena. The mechanism of these switching phenomena is thermal effect. Conductivity of the glasses containing less than 40 molar percent of V205 has been measured in the range of -18℃ to 120℃. D.C. conduction mechanism of those glasses is electron hopping conduction caused by movement of electrons from low valence ion sites to those of high valence through the oxygen bridges.

N.Q.R. 추적장치

조동산,정환재 全南大學校 師範大學 科學敎育硏究所 1981 科學敎育硏究誌 Vol.6 No.1

A Robinson type continuous r. f. oscillator has been constructed for N.Q.R Spectroscope by employing field effect transistors and I.C.. Bidirectional square wave generator, lock-in amp, motordrive sγstems are built into the system. The sweep sange is from 1 MHz to 20 MHz. The NQR system has been tested with N14 in hexainethylentetramine.

V2O5-CuO-P2O5系 유리半導體의 電氣的 特性에 關한 硏究

趙東山 全南大學校 師範大學 科學敎育硏究所 1981 科學敎育硏究誌 Vol.6 No.1

Phosphate glasses containing two transition metal oxides V205, CuO have been prepared, their electronic conduction and electrical switching characteristics were investigated. Electronic conductivity increases with rising ambient temperature and increasing the amount of transition metal oxides. Electronic conduction is caused by the hopping motion of the electrons among transition metal ions (TMI) which are in different states under the electric field 6×104 volt/cm. Glasses, which have P205 content less than 40 mole percent, showed elec trical switching phenomena. The electrical switching field decreases with increasing both ambient temperature and transition metal oxide contents. The electrical switching field is lower in the glasses which have higher electronic conductivity. The electrical switching is caused by the joule heat in the glass specimens. The mechanism of these switching phenomena is proγed to be electrothermal effect.

高等學校 Energy 敎育을 위한 實態調査와 資料開發(Ⅱ)

趙東山,金昌大 全南大學校 師範大學 科學敎育硏究所 1983 科學敎育硏究誌 Vol.8 No.1

The energy crisis has been heightened by the shortage of energy resources and the man’s expanding needs for energy, resulting in the social, economical and environmental difficulties. To overcome and solve such difficulties, it is very important to reflect the energy problems on the high school curriculum and to educate students. In this paper, the contents of science textbooks being used in the American high schools have been investigated. especially the contents related to energy. The results have been analyzed and compared with those obtained previously in the Japanese and the Korean textbooks. The formation. recognition and attitude of energy concepts of teachers and students have been also examined. With this results. we have suggested a model for developing the teaching materias for energy education appropriate to the high school level.

산화물 소결체에서 전기적 Switching 기구

조동산,김화택 한국세라믹학회 1978 한국세라믹학회지 Vol.15 No.3

Sintering oxide which was prepared by sintering at $1200^{\circ}C$ the mixture of ${\gamma}$-$Fe_2O_3$ and $Sb_2O_3$ in 2 : 1 mol ratio, showed 1st electrical switching and stable 2nd switching when D.C. voltage was applied. This electrical switching mechanism was known to be thermal mechanism from dependence of environmental temperature of threshold Voltage(Vm), Current(Im) and the conductivity of the current filament of the sintering oxide.

(100-x)V2O5 (x)NiO Glass의 電氣的 Switching 特性

趙東山 全南大學校 師範大學 科學敎育硏究所 1977 科學敎育硏究誌 Vol.2 No.1

After melting powder compounds for 2 hours at 1000°C and then quenching, the (100-x)V2O5 (x)NiO glasses of various compositions(x ranges from 10 to 40) were prepared in order to apply to the switching devices. The electrical switching effect was observed and this electrical switching machanism can be explained in terms of thermal effect, based on the measurment of pysical preperties of the these glasses.

Si-In₂O₃p-n Heterojunction 太陽電池의 電氣的 光學的 特性

朴泰永,庾基洙,趙東山 圓光大學校 1980 論文集 Vol.14 No.2

In(NO₃)₃水溶液을 300˚C로 加熱한 Si 基板 위에 Spray 하는 새로운 方法으로 Si-In₂O₃p-n Heterojunction 太陽電池를 製作하였다. 이 太陽電池는 整流性 接合이며 400 nm 에서 1200 nm 까지 光電感度를 갖고 太陽 Energy 變換效率은 8.72%였다. Si-In₂O₃p-n Heterojunction solar cells have been prepared by spraying the In(NO₃)₃hydro-solution on the Si substrate heated at 300˚C. These solar cells are rectifying junctions, and show the photosensitivity in the wavelength range from 400 nm to 1200 nm. The solar energy conversion rate of these cells are 8.72%.

Chemical Transport Reaction Method로 성장한 CdGa₂Se₄: Co 단결정의 광학적 특성에 관한 연구

김창대,정해문,조동산 木浦大學校基礎科學硏究所 1986 基礎科學硏究誌 Vol.4 No.-

The crystal structure of CdGa₂Se₄ single crystal belongs to the defect chalcopyrite (space group S₄??) family, and the lattice constants are a=5.756A, c=10.820A. Optical absorption studies showed that CdGa₂Se₄ and CdGa₂Se₄: Co single crystals have indirect band gaps of 2.29 and 2.18eV at room temperature, respectively. The absorption peaks due to the impurity cobalt in CdGa₂Se₄: Co single crystal doped cobalt as impurity are appeared at 775nm??, 1580nm?? 2420nm??. The three absorption peaks are attributed to ⁴A₂(⁴F) →⁴T₁(⁴P), ⁴A₂(⁴F) →⁴T₁(⁴F), ⁴A₂(⁴F) → ⁴T₂(⁴F) transition of ?? ion entered the substitutional tetrahedral sites. The crystal field parameter Dq and the Reach parameter B were found to be ??. The temperature coefficients are ?? and ?? for CdGa₂Se₄ single crystals, ?? and ?? for CdGa₂Se₄: single crystals, respectively.